1. Field of the Invention
The present invention relates to respiratory interface devices for transporting a gas to and/or from an airway of a user which include, but are not limited to, a mask having a flexible faceplate or patient contacting cushion, and, in particular, to a flexible respiratory interface device wherein the support assembly is structured to allow gas to pass therethrough including a flow as a radial exhaust.
2. Description of the Related Art
A variety of respiratory masks are known which cover the areas surrounding the nose and/or mouth of a human user. Typically, gases can be provided at a positive pressure within the mask for consumption by the user. The uses for such masks include high altitude breathing (aviation applications), swimming, mining, fire-fighting, and various medical diagnostic and therapeutic applications. The masks are, typically, held in place by a support assembly having one or more straps.
Support assemblies may include a plurality of straps disposed in various configurations depending upon the mask and the user's preference. Generally, however, the support assembly includes at least one strap that extends about a user's head while having the two ends coupled to the mask disposed on the user's face. Additional straps may position the primary strap in a comfortable location, and/or may assist in positioning and maintaining the mask in the proper location. Thus, at least one strap extends over the user's face and, more typically, over the user's cheeks.
Straps may be made from various materials such as, but not limited to, fabric, plastic, or silicone. In some embodiments, the straps define, or enclose, a conduit that is in fluid communication with the mask, which may eliminate the need for a separate conduit coupled directly to the mask. The conduit may also be in fluid communication with a device capable of generating a flow of breathing gas or providing gas at an elevated pressure. The straps, even straps made from a breathable material, may become uncomfortable over a period of time. That is, the straps tend to remain positioned over the same area of the user's face and may trap heat and sweat thereunder. This is especially true when the strap encloses a conduit as such straps do not breath.
Further, certain types of masks include an exhaust port structured to allow expired gases to be vented to the atmosphere. The expired gases may “jet” from the exhaust port in a concentrated stream. This stream may cross the user's face, or may be directed to an adjacent space; such as the space occupied by people in close proximity to the user, e.g. a bed partner. Thus, the exhaust stream may be uncomfortable for either the user, another person, or both.
Accordingly, there is a need for a support assembly that allows for airflow under at least portions of the strap assembly. There is a further need for a support assembly that assists in dissipating an exhaust jet from a mask.